利用ListView做多级菜单

在开发Android的时候，需要做一个多级的树状菜单，而且级数可能会变化，查阅网上很多材料，受到很大启发，之前网上找过一个，当时完成了功能要求，但存在几个问题，今天重新拿出原来长长的代码，经过增删及自己的理解，终于整理出来啦。

源码资源下载http://download.csdn.net/detail/op_kapu/5815691

大体的思路：点开父亲节点的时候，把子节点添加到listview中，刷新listview

关闭父亲节点的时候，把子节点从listview中删除，刷新listview

先上图：

然后是代码~

TreeNode.java

package com.example.treetest;

import java.util.ArrayList;
import java.util.List;

/**
 * 树节点对象
 *
 * @author Kapu
 */
public class TreeNode {
	private String title;
	private boolean hasChildren;
	private int Level;
	private List<TreeNode> children = new ArrayList<TreeNode>();
	private boolean expanded;

	public void addChild(TreeNode node) {
		this.hasChildren = true;
		this.children.add(node);
	}

	public String getTitle() {
		return title;
	}

	public void setTitle(String title) {
		this.title = title;
	}

	public int getLevel() {
		return Level;
	}

	public void setLevel(int level) {
		Level = level;
	}

	public boolean isExpanded() {
		return expanded;
	}

	public void setExpanded(boolean expanded) {
		this.expanded = expanded;
	}

	public boolean hasChildren() {
		return hasChildren;
	}

	public void hasChildren(boolean hasChildren) {
		this.hasChildren = hasChildren;
	}

	public List<TreeNode> getChildren() {
		return children;
	}

	public void setChildren(List<TreeNode> children) {
		this.hasChildren = true;
		this.children = children;
	}
}

TreeViewAdapter.java

package com.example.treetest;

import java.util.List;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.TextView;

public class TreeViewAdapter extends BaseAdapter {  

    private LayoutInflater mInflater;
    private List<TreeNode> mfilelist;
    private Bitmap mIconCollapse;   //- ， 收缩
    private Bitmap mIconExpand;  	//+ ，展开

    public TreeViewAdapter(Context context, List<TreeNode> treeNodes) {
        super();
        mInflater = LayoutInflater.from(context);
        mfilelist = treeNodes;
        mIconCollapse = BitmapFactory.decodeResource(context.getResources(), R.drawable.plus);
        mIconExpand = BitmapFactory.decodeResource(context.getResources(), R.drawable.minus);
    }  

	public int getCount() {
        return mfilelist.size();
    }  

	public Object getItem(int position) {
        return position;
    }  

	public long getItemId(int position) {
        return position;
    }  

	public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder holder;
        convertView = mInflater.inflate(R.layout.tree_node, null);
        holder = new ViewHolder();
        holder.text = (TextView) convertView.findViewById(R.id.treetext);
        holder.icon = (ImageView) convertView.findViewById(R.id.icon);
        convertView.setTag(holder);  

        final TreeNode obj = mfilelist.get(position);  

        int level = obj.getLevel();
        holder.icon.setPadding(	15 * (level + 1),
                holder.icon.getPaddingTop(), 0,
                holder.icon.getPaddingBottom());
        holder.text.setText(obj.getTitle());
        if (obj.hasChildren()&& (obj.isExpanded() == false)) {
            holder.icon.setImageBitmap(mIconCollapse);
        } else if (obj.hasChildren() && (obj.isExpanded() == true)) {
            holder.icon.setImageBitmap(mIconExpand);
        } else if (!obj.hasChildren()) {
            holder.icon.setImageBitmap(mIconCollapse);
            holder.icon.setVisibility(View.INVISIBLE);
        }
        return convertView;
    }  

    class ViewHolder {
        TextView text;
        ImageView icon;  

    }  

} 

MainActivity.java

package com.example.treetest;

import java.util.ArrayList;
import java.util.List;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.AdapterView.OnItemClickListener;
import android.app.Activity;
public class MainActivity extends Activity{

	/** 左侧树 */
	private List<TreeNode> nodes = new ArrayList<TreeNode>();
	private TreeViewAdapter treeViewAdapter = null;
	/** 目录树数据 */
	private ListView dir;
	/** 当前在左侧目录选中的位置 */
	int currentPosition;

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        dir = (ListView) findViewById(R.id.dir);

		//初始化数据
        List<TreeNode> treeNodeList = new ArrayList<TreeNode>();

        TreeNode tree0 = new TreeNode();
        tree0.setLevel(0);
        tree0.setTitle("第一章");
        	List<TreeNode> treeNodeList0 = new ArrayList<TreeNode>();
        	TreeNode tree00 = new TreeNode();
            tree00.setLevel(1);
            tree00.setTitle("第一课");

            TreeNode tree01 = new TreeNode();
            tree01.setLevel(1);
            tree01.setTitle("第二课");
            		List<TreeNode> treeNodeList00 = new ArrayList<TreeNode>();
            		TreeNode tree000 = new TreeNode();
            		tree000.setLevel(2);
            		tree000.setTitle("第二课第一节");

            		TreeNode tree001 = new TreeNode();
            		tree001.setLevel(2);
            		tree001.setTitle("第二课第二节");
            		treeNodeList00.add(tree000);
            		treeNodeList00.add(tree001);
            tree01.setChildren(treeNodeList00);
            treeNodeList0.add(tree00);
            treeNodeList0.add(tree01);
        tree0.setChildren(treeNodeList0);
        tree0.hasChildren(true);

        TreeNode tree1 = new TreeNode();
        tree1.setLevel(0);
        tree1.setTitle("第二章");

        treeNodeList.add(tree0);
        treeNodeList.add(tree1);

        nodes = treeNodeList;

		dir.setDivider(null);
        treeViewAdapter = new TreeViewAdapter(this, nodes);
		dir.setAdapter(treeViewAdapter);

		dir.setOnItemClickListener(new OnItemClickListener() {
			public void onItemClick(AdapterView<?> l, View v, int position,
					long id) {

				// 此节点下没有子节点,即某一个小节
				if (!nodes.get(position).hasChildren()) {
					return;
				}

				// 假如 此父节点下有子节点，且 已展开  关闭的时候删除
				if (nodes.get(position).isExpanded()) {
					nodes.get(position).setExpanded(false);
					TreeNode element = nodes.get(position); // 先得到该 父节点

					ArrayList<TreeNode> temp = new ArrayList<TreeNode>();
					// 循环得到 子节点
					for (int i = position + 1; i < nodes.size(); i++) {
						if (element.getLevel() >= nodes.get(i).getLevel()) {
							break;
						}
						temp.add(nodes.get(i));
					}

					nodes.removeAll(temp);
					treeViewAdapter.notifyDataSetChanged();
				} else {
					// 假如 此父节点未展开，则 展开 展开的时候增加
					TreeNode obj = nodes.get(position);
					obj.setExpanded(true);
					int level = obj.getLevel(); // 父节点级数
					int nextLevel = level + 1; // 子节点 级数 = 父节点级数+1
					int temp = position;//临时位置
					// 循环 得到 此父节点的所有子节点
					for (TreeNode element : obj.getChildren()) {
						element.setLevel(nextLevel);
						element.setExpanded(false);
					temp = temp+1;
						nodes.add(temp, element);
					}
					// 将已变化的nodes列表 刷新
					treeViewAdapter.notifyDataSetChanged();
				}
			}
		});
    }
}